I´m trying to make a casette to test my programs on a real nes.
I´m using eprom´s for the chr- and prg-data. To start with I have made a mapper-0 cart and using arkanoid to verify that it is working correct. But i dont get it to work properly. When I start the game, the background looks like garbage, but I can hear music plying. I press start and gets to the first level. Now I can see the "pad" ant the ball clearly, but the background is still completely messed up. I thought that maby it was the eprom that isn´t fast enough. But if so, I can´t understand why the sprites gets right. I´v read that the ppu accesses the rom in about 4MHz, that makes a cycle-time of 250ns and the eprom I use is 120ns.
I can´t understand why it is not working, please help.